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EXTREMITY AMPUTEES. CANADIAN PROSTHETICS & ORTHOTICS JOURNAL, VOLUME 1, ISSUE 2, 2018; ABSTRACT, POSTER PRESENTATION AT THE AOPA’S 101ST NATIONAL 
ASSEMBLY, SEPT. 26-29, VANCOUVER, CANADA, 2018.   DOI: https://doi.org/10.33137/cpoj.v1i2.32015                                                                           

 

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OPEN  ACCESS 

 

AOPA’S 101 ST NATIONAL ASSEMBLY ABSTRACTS, SEPTEMBER 26-29, VANCOUVER, CANADA, 2018 
 

ABSTRACT (POSTER PRESENTATION) 

EFFECT OF LEVEL OF AMPUTATION ON POSTURAL STEADINESS AMONG 

LOWER EXTREMITY AMPUTEES 

Arianna Medema, Douglas Henness, Kendra Steinhorst, Robert Moauro, Michael Reuland, Robert Whelan, 

Shawna Kester, Hamid Bateni*  

Physical Therapy Program, Northern Illinois University, DeKalb, IL, USA. 

* Email: hbateni@niu.edu 

DOI: https://doi.org/10.33137/cpoj.v1i2.32015  
 

INTRODUCTION 

Increased rate of fall, reduced balance confidence and 

increased fear of falling is reported for lower extremity 

amputees.1 Fall rate also increases at higher levels of 

amputation1. This study aims to compare postural 

steadiness of different levels of lower extremity 

amputees through comparison of time and frequency 

domain variables of postural sway.  

METHODS 

Data from six lower extremity amputees (2 unilateral 

trans-tibial [UTT], 1 bilateral trans-tibial [BTT], 2 

unilateral transfemoral [UTF] and 1 unilateral hip 

disarticulation [UHD]) with the average age of 51±16 

years was analyzed. Participants were instructed to stand 

(bare feet - heels together, 5-7 degrees toe-out) on a force 

platform and were tested for three standing conditions: a- 

eyes open, b- eyes closed and c- standing on Airex 2.5” 

thick balance pad (www.airex.com). Each test was 

repeated three times (block randomized). Force platform 

data were collected for 35 seconds (Fs=100). 

Anteroposterior and mediolateral time series data were 

filtered through a fourth-order zero phase Butterworth 

low-pass filter with cut-off frequency of 5 Hz. The first 

8 sec. and last 2 sec. of data were cut off to remove any 

potential lead-in/out effect.  

RESULTS 

Mean ML distance COP sway was significantly affected 

by both level of amputation (F3,5=15.08 P<.0001) and 

standing condition (F2,5=7.45 P=.0017). Maximum 

velocity of ML and amputation level were also 

significantly related (F3,5=8.71 P<.0001). Root Mean 

Square distance from central sway point in medio-lateral 

direction, which is known to be single best predictor of 

future falling risk was affected by both level of 

amputation and standing conditions (P=0.0008). Total 

power computed as the integrated area of power 

spectrum also was significantly affected by both 

amputation and standing conditions (p<.0001). Resultant 

centroidal frequency was affected by level of amputation 

(p=.017). 

Figure 1: comparison of ML distance of postural sway for 

different levels of amputation. BTT/UTT=bilateral/unilateral 

trans-tibial, UTF= unilateral trans-femoral, UHD= unilateral 

hip disarticulation. Conditions 1=eyes open, 2=eyes close, 3= 

standing on the foam. Note significant differences between 

unilateral and bilateral amputees. 

CONCLUSION 

Changes in time and frequency domain variables are 

significantly related to the level of amputation. Variation 

in frequency domain variable may be indicating 

application of different strategies in postural steadiness 

and control of sway.  

SIGNIFICANCE 

Impact of level of amputation of frequency domain 

variables of postural sway may lead to new assessment 

of prosthetic limb.  

REFERENCES 

1- Miller WC et al., The prevalence of risk factors of falling 

and fear of falling among lower extremity amputees. Arch. 

Phys. Med. Rehabil. 2001;82: 1031-1037. 

DOI:10.1053/apmr.2001.24295 

DISCLOSURE 

No conflict of interest exists for this study. 

mailto:hbateni@niu.edu
https://doi.org/10.33137/cpoj.v1i2.32015
https://doi.org/10.1053/apmr.2001.24295

